(mediaeval folklore) A femaledemon which comes to men, especially monks, in their dreams to seduce them and have sexual intercourse, drawing energy from the men to sustain themselves, often until the point of exhaustion or death.

1977 Italo Calvino, The Castle of Crossed Destinies, Part 2, Chapter 5, 1969. Translated from Italian by William Weaver.

When the Sabbath is caught by the first ray of the rising sun, all the witches and the vampires, incubi and succubi, take flight, some transforming themselves into noctules, some into other bats, some into still other species of Chiroptera.